Silas g



UNITED STATEMS PATENT OFFICE.

SILAS G. RANDALL, OF MIDDLEBURY, VERMONT.

KEEPING AIR-SPRINGS SUPPLIED WITH AIR.

Specification of Letters Patent No. 23,497, dated April 5, 1859.

To all whom t may concern:

Be it known that I, SILAS G. RANDALL, of Middlebury, in the county ofAddison and State of Vermont, have invented a new and useful manner ofsupplying air springs with air when said springs are applied to cars,carriages, or other locomotive machines requiring them; and I do herebydeclare the following to be a full, clear, and exact description of thesame, reference being had to the accompanying drawings, making a part ofthis speciiication, in which- Figure l, represents a side view of acommon truck such as are-used with cars, and Fig. 2, represents atransverse section through the air springs, and their communicatingparts.

Similar letters of reference where they occur in the separate iguresdenote like parts in both of them.

The use of air springs on cars, carriages, &c., has been practicallyvabandoned, from the ditiiculty in keeping them supplied with air, orpreventing their leaking. I do not propose to make air springs proofagainst losing their confined air, as this is found to be impracticableunder the heavy and varying pressure that comes upon them, but Iovercome this evil, by forcing a supply into the springs during theentire period that the car or carriage is in motion, so that the springsare constantly effective when in use, whatever may be the leakage fromwear, or sudden ars or pressure.

My invention consists in so connecting an air pump or pumps to the airsprings of cars, carriages, &c., and further attaching the piston orpistons of said pumps to the running gear, or other moving part thereof,as that when said car or carriage is in motion, the air pump or pumpsshall be constantly furnishing air to take the place of that lost byleakage.

To enable others skilled in the art to make anduse my invention I willproceed to describe the same with reference to the drawings.

A, represents a truck frame, and B, the wheels supporting it. On a crossplate a, extending from one side to the other of said truck frame, Iarrange two air springs which may be composed substantially of metalliccylinders Z), b, with pistons c, o, fitting snugly therein by packing orotherwise, so that they may rise and fall therein. To each of thesepistons, are attached rods d, d, which support the bolster C, on whichone end of the car body rests.

e, is an air pipe or tube which connects with the air chambers of eachspring so that one pump may supply both with air, though if foundpreferable each spring may have its own pump or one air pump may supplythe springs of an entire train. An air pump on the locomotive to supplyan entire train of cars may also be used, the only objection to such usebeing because it would involve the trouble of making elastic air tightconnections between the cars and locomotive.

f, is an ordinary air pulnp, and t', a piston working in it.

n, is a connecting rod, connecting the piston z' to a wrist pin on oneof the wheels, or

to a crank or eccentric on the axle, so as to reciprocate said pistonz', in the pump. A valve 5, covers an opening leading from the pump, tothe chamber under the piston c, by which said chamber is filled withair; and the opposite spring is suplied through the pipe o. An opening 6is made through the piston of the opposite spring from the pump saidopening being covered by a safety valve or spring 7, so that any excessof air over a given density may escape.

The air enters the air pump through an opening or seat that has a valve2, snugly i'itting it, said valve having attached to it, a valve rod 3,and a spring 4E, to close it after the air has opened it and rushed into fill the vacuum created by the drawing forward of the piston z'. Thenthe piston z', is making the stroke that forces air into the springs thevalve 2, is driven tight to its seat, and the air in the pump driven upthrough the opening covered by the valve 5, and so on.

Having thus fully described the nature and object of my invention, whatI claim therein as new and desire to secure by Letters Patent, is-

So combining an air spring, and an air pump, or its equivalent, with acar, carriage,

or other moving conveyance, as that the motion of said car, carriage, orother. conveyance shall through such air supplier, keep the air springssupplied with air, substantially as herein set forth.

SILAS G. RANDALL.

I/Vitnesses:

EDw. F. BROWN, Trios. H. UPPERMAN.

